Magnetic resonance histology to image the brains of small animals is a critical technology for biology, toxicology, and drug discovery research. To achieve high-resolution, the radio frequency (RF) probes used to obtain the images must have a very high signal-to-noise ratio. We propose an innovative RF probe fabricated from high-temperature superconducting material. The probe achieves high signal-to-noise ratio through the use of superconducting coil elements. The novel cryogenic design enables precise control of the coil's temperature. The probe design provides a solenoid coil surrounding the sample for excellent coupling to the primary magnetic field, cryogenic cooling distributed uniformly throughout the coil, and superinsulation that enables the coil to be located very close to the sample. The probe design can accommodate samples up to 2 cm in diameter, enabling MR histology of both mouse and rat brains. In Phase I, we will prove the feasibility of the superconducting RF coil by: (1) fabricating a prototypical coil element, and (2) demonstrating the element's performance under prototypical, cryogenic conditions. PROPOSED COMMERCIAL APPLICATION: The key application for the RF probe is MR histology of small animal specimens. MR histology (MRH) promises enormous benefits because it is extremely fast, allows use of unique "proton stains," produces three-dimensional images of tissues, and produces digital images that are easily shared. MRH has enormous screening potential because tissues can be excised and scanned immediately. As a result, the RF probe developed in this program will enable tremendous cost savings in the fields of drug discovery, toxicology, and the study of fundamental physiology and disease mechanisms. Customers for the probe will include pharmaceutical companies, research laboratories, and MR pathology service providers.